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WIP: Use dispatch_to_series for combine_const #22751

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40 changes: 36 additions & 4 deletions pandas/core/frame.py
Original file line number Diff line number Diff line change
Expand Up @@ -4924,10 +4924,42 @@ def _combine_const(self, other, func, errors='raise', try_cast=True):
if lib.is_scalar(other) or np.ndim(other) == 0:
return ops.dispatch_to_series(self, other, func)

new_data = self._data.eval(func=func, other=other,
errors=errors,
try_cast=try_cast)
return self._constructor(new_data)
elif (np.ndim(other) == 1 and isinstance(other, np.ndarray) and
len(other) == len(self.columns)):
try:
right = np.broadcast_to(other, self.shape)
except AttributeError:
# numpy < 1.10
right = np.tile(other, self.shape)
return ops.dispatch_to_series(self, right, func)

elif (np.ndim(other) == 1 and
isinstance(other, (tuple, np.ndarray)) and
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There is a test for that goes through this path with a tuple, but none with a list. IIRC, no tests fail if list is included here.

Similarly, in the case above, only np.ndarray cases are tested. Should tuple and/or list be allowed?

len(other) == len(self) != len(self.columns)):
# tests include at least 1 tuple in this case
right = np.array(other)[:, None]
try:
right = np.broadcast_to(right, self.shape)
except AttributeError:
# numpy < 1.10
right = np.tile(right, self.shape)
return ops.dispatch_to_series(self, right, func)

elif np.ndim(other) == 1:
raise ValueError("Shape incompatible")

elif np.ndim(other) == 2 and other.shape == self.shape:
return ops.dispatch_to_series(self, other, func)

elif (np.ndim(other) == 2 and isinstance(other, np.ndarray) and
other.shape[0] == 1 and other.shape[1] == len(self.columns)):
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Should the transposed case be supported?

other = np.broadcast_to(other, self.shape)
return ops.dispatch_to_series(self, other, func)

elif np.ndim(other) > 2:
raise ValueError("Wrong number of dimensions", other.shape)

raise ValueError(getattr(other, 'shape', type(other)))

def combine(self, other, func, fill_value=None, overwrite=True):
"""
Expand Down
139 changes: 0 additions & 139 deletions pandas/core/internals/blocks.py
Original file line number Diff line number Diff line change
Expand Up @@ -1313,145 +1313,6 @@ def shift(self, periods, axis=0, mgr=None):

return [self.make_block(new_values)]

def eval(self, func, other, errors='raise', try_cast=False, mgr=None):
"""
evaluate the block; return result block from the result

Parameters
----------
func : how to combine self, other
other : a ndarray/object
errors : str, {'raise', 'ignore'}, default 'raise'
- ``raise`` : allow exceptions to be raised
- ``ignore`` : suppress exceptions. On error return original object

try_cast : try casting the results to the input type

Returns
-------
a new block, the result of the func
"""
orig_other = other
values = self.values

other = getattr(other, 'values', other)

# make sure that we can broadcast
is_transposed = False
if hasattr(other, 'ndim') and hasattr(values, 'ndim'):
if values.ndim != other.ndim:
is_transposed = True
else:
if values.shape == other.shape[::-1]:
is_transposed = True
elif values.shape[0] == other.shape[-1]:
is_transposed = True
else:
# this is a broadcast error heree
raise ValueError(
"cannot broadcast shape [{t_shape}] with "
"block values [{oth_shape}]".format(
t_shape=values.T.shape, oth_shape=other.shape))

transf = (lambda x: x.T) if is_transposed else (lambda x: x)

# coerce/transpose the args if needed
try:
values, values_mask, other, other_mask = self._try_coerce_args(
transf(values), other)
except TypeError:
block = self.coerce_to_target_dtype(orig_other)
return block.eval(func, orig_other,
errors=errors,
try_cast=try_cast, mgr=mgr)

# get the result, may need to transpose the other
def get_result(other):

# avoid numpy warning of comparisons again None
if other is None:
result = not func.__name__ == 'eq'

# avoid numpy warning of elementwise comparisons to object
elif is_numeric_v_string_like(values, other):
result = False

# avoid numpy warning of elementwise comparisons
elif func.__name__ == 'eq':
if is_list_like(other) and not isinstance(other, np.ndarray):
other = np.asarray(other)

# if we can broadcast, then ok
if values.shape[-1] != other.shape[-1]:
return False
result = func(values, other)
else:
result = func(values, other)

# mask if needed
if isinstance(values_mask, np.ndarray) and values_mask.any():
result = result.astype('float64', copy=False)
result[values_mask] = np.nan
if other_mask is True:
result = result.astype('float64', copy=False)
result[:] = np.nan
elif isinstance(other_mask, np.ndarray) and other_mask.any():
result = result.astype('float64', copy=False)
result[other_mask.ravel()] = np.nan

return result

# error handler if we have an issue operating with the function
def handle_error():

if errors == 'raise':
# The 'detail' variable is defined in outer scope.
raise TypeError(
'Could not operate {other!r} with block values '
'{detail!s}'.format(other=other, detail=detail)) # noqa
else:
# return the values
result = np.empty(values.shape, dtype='O')
result.fill(np.nan)
return result

# get the result
try:
with np.errstate(all='ignore'):
result = get_result(other)

# if we have an invalid shape/broadcast error
# GH4576, so raise instead of allowing to pass through
except ValueError as detail:
raise
except Exception as detail:
result = handle_error()

# technically a broadcast error in numpy can 'work' by returning a
# boolean False
if not isinstance(result, np.ndarray):
if not isinstance(result, np.ndarray):

# differentiate between an invalid ndarray-ndarray comparison
# and an invalid type comparison
if isinstance(values, np.ndarray) and is_list_like(other):
raise ValueError(
'Invalid broadcasting comparison [{other!r}] with '
'block values'.format(other=other))

raise TypeError('Could not compare [{other!r}] '
'with block values'.format(other=other))

# transpose if needed
result = transf(result)

# try to cast if requested
if try_cast:
result = self._try_cast_result(result)

result = _block_shape(result, ndim=self.ndim)
return [self.make_block(result)]

def where(self, other, cond, align=True, errors='raise',
try_cast=False, axis=0, transpose=False, mgr=None):
"""
Expand Down
6 changes: 0 additions & 6 deletions pandas/core/internals/managers.py
Original file line number Diff line number Diff line change
Expand Up @@ -373,9 +373,6 @@ def apply(self, f, axes=None, filter=None, do_integrity_check=False,
align_keys = ['new', 'mask']
else:
align_keys = ['mask']
elif f == 'eval':
align_copy = False
align_keys = ['other']
elif f == 'fillna':
# fillna internally does putmask, maybe it's better to do this
# at mgr, not block level?
Expand Down Expand Up @@ -511,9 +508,6 @@ def isna(self, func, **kwargs):
def where(self, **kwargs):
return self.apply('where', **kwargs)

def eval(self, **kwargs):
return self.apply('eval', **kwargs)

def quantile(self, **kwargs):
return self.reduction('quantile', **kwargs)

Expand Down
16 changes: 16 additions & 0 deletions pandas/core/ops.py
Original file line number Diff line number Diff line change
Expand Up @@ -1717,6 +1717,22 @@ def column_op(a, b):
return {i: func(a.iloc[:, i], b)
for i in range(len(a.columns))}

elif np.ndim(right) == 2 and right.shape == left.shape:
# ndarray with same shape

def column_op(a, b):
return {i: func(a.iloc[:, i], b[:, i])
for i in range(len(a.columns))}

elif (np.ndim(right) == 2 and
right.shape[0] == 1 and
right.shape[1] == len(left.columns)):
# operate row-by-row

def column_op(a, b):
return {i: func(a.iloc[:, i], b[0, i])
for i in range(len(a.columns))}

else:
# Remaining cases have less-obvious dispatch rules
raise NotImplementedError(right)
Expand Down